//
//  Book.h
//  InstanceDemo
//
//  Created by fangyuan ding on 2020/10/27.
//  Copyright © 2020 fangyuan ding. All rights reserved.
//

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface Book : NSObject

/** 获取单例 */
+ (instancetype)instance;

/** 打印文本 */
+ (void)print:(NSString*)msg;
@end

NS_ASSUME_NONNULL_END
